We have a great line up of Tutorials on Percona Live, London. I hand picked number of them after seeing outstanding speaker Performance in other Places. Let me tell in little bit more details about people we have invited and their talks.

Yoshinori Matsunobu Talk on Linux Hardware and Optimizations for MySQL at Oreilly MySQL Conference and Expo was phenomenal. I wrote about it before and I’m very happy Yoshinori is able to come to London and talk more about this topic. Yoshinori put probably months of testing and research in his talk …

A friend recently bought a GM car. I proceeded to inform him that I am shorting GM stock (technically a put option). He was shocked. “But they make great cars,” he exclaimed. I responded, “I’m not shorting the cars, I’m shorting the company.” Why am I recounting this exchange? Because I believe that the new wave of NoSQL companies—as opposed to the rebranded ODBMS—presents the same situation. I am long the products, but short the companies.
Let me explain. NoSQL companies have built some very cool products that solve real business problems. The challenge is that they are all open source products serving niche markets. They have customer funnels that are simply too small to sustain the companies given their low conversion/monetization rates.
These companies could certainly be tasty acquisition targets for companies that actually make money. But as standalone companies, sadly, I would short them. On that note, I am off to …

If you're not reading this blog in a feed reader, you'll notice two little badges on the right hand side advertising Oracle Openworld and JavaOne. I'm speaking at both events this fall, first at the JDBC Birds-of-a-Feather on Monday night:

Session Title: JDBC and Rowset Community Discussion
Venue/Room: Hilton San Francisco - Imperial Ballroom A
Date and Time: 10/3/11, 08:00 PM

On Wednesday I'll be presenting a session on developing scalable applications with Java and MySQL:

Session Title: Diagnosing Scalability Issues in Java Applications on MySQL
Venue / Room: Marriott Marquis - Golden Gate B
Date and Time: 10/5/11, 10:00 AM

I'll also be hanging around in Mark Leith's session on MySQL Enterprise Monitor:

Session Title: Getting to Know MySQL Enterprise Monitor
Venue / Room: Marriott Marquis - Golden Gate C1
Date and Time: 10/4/11, 10:15

There's a very …

I’m pleased to announce the release of DBD::mysql, the MySQL Perl client, 4.020. The release has several great fixes provided by the community, and in particular from Masahiro Chiba, who fixed several issues pertaining to prepared statement support as well as UTF8 support, something that I myself have had a difficult time fixing and testing.

From the Change log:

2011-08-15 Patrick Galbraith (4.020)
* Numerous (!! Thank you!!) fixes for prepared statements: Masahiro Chiba
– Chop blanks fixed
– UTF8 improvements
– fixed memory allocation for BLOBs
– auto-reconnect
* Fix in leak test, which failed sometime due to first assignment $prev_size over
paging (Masahiro Chiba)
* Catalog test allows use of schemas other than ‘test’ (Masahiro Chiba)
* Documentation fix for auto_reconnect (Karen Etheridge )
* Win32 and general installation fixes (Alexandr …

One of the typical problems I see setting up ext2/3/4 file system is sticking to defaults when it comes to behavior on errors. By default these filesystems are configured to Continue when error (such as IO error or meta data inconsistency) is discovered which can continue spreading corruption. This manifests itself in a worst way when device have some “flapping” problems returning errors every so often as this would cause some random pieces of data and meta data to be lost. Not good for system running mySQL Server. As far as I understand this problem is limited to EXT2/3/4 while over systems like XFS will not continue if consistency problems are discovered.

So how can you check what error behavior mode your file system has ? Run dumpe2fs /dev/sda1 and you will get something like this:

dumpe2fs 1.41.14 (22-Dec-2010)
Filesystem volume name:
Last mounted on: /mnt/data
Filesystem UUID: …

Update 2012-01-09: I have now been able to understand the poor(ish) results in this benchmark. They are very likely due to a bad hardware setup and neither Galera nor InnoDB is to blame. See http://openlife.cc/blogs/2012/january/re-doing-galera-disk-bound-benchmark

People commenting on my results for benchmarking Galera on a disk bound workload seemed to be confused by the performance degrading when writing to more than one master, and not convinced at my speculations on the reasons. Since sysbench 0.5 has the benchmarks in the form of LUA scripts, it was temptingly easy to tweak those a little to see if my speculations were correct. So yesterday I did run tests again with a slightly modified sysbench workload. …

How To Migrate Joomla Content (Articles) Using phpMyAdmin

Joomla is a very popular Content Management System (CMS). This article applies to Joomla 1.5 content (Article) migration to Joomla 1.7 using phpMyAdmin database tool.

Hanging out in #mysql on freenode the other day, I overheard someone saying that the reason to use connection pools with MySQL is because JDBC connections are expensive to create. That is true out of the box, but mostly because the out of the box behavior of MySQL's JDBC driver is to be standards-compliant. If you know that your DBA and your developers aren't doing crazy things with the database (changing configurations without letting the developers know, going around the "standard" API calls to start/end transactions, etc), then you can get to the point where connection setup is no slower than any other API. Does this mean you shouldn't use a connection pool? NO! (more on this next week).

Here's an iterative overview of the changes made in configuration, and how they affect what queries the driver does on initialization.

First, asking the driver to connect with default configuration results in the following statements being …

It has been a while since I have posted any updates on the XtraBackup Manager front and I apologise for that. Between taking some time off for vacation (how dare I!?) and various different tasks at work snagging my focus away from XBM, I really haven't had much time to work on it.
(Un)fortunately last week we encountered a DB failure that would have been much faster and less painful to recover from had we had XtraBackup Manager finished and in place. While it was a pretty rough week for us DBAs working on addressing the failure, the silver lining is that we now have a concrete example to point to for the importance of the XtraBackup Manager project.
The silver lining in the long story cut short is that I now have the support I need to focus most of my time on XBM again.
So what have I been working on?
I have added support for materialzed backups to the "Continuous Incremental" backup strategy.
I have proceeded with …

Linuxcon was a celebration of twenty years of Linux. I remember colleagues telling me to try the funny little operating system for PCs instead of a BSD variant, their excitement, and making distro ‘floppies’ for . The time has flown, Linux has become a core infrastructure for IT, and many technologies built upon upon Linux has flourished. But could it be better? At least for the database world, things could be better.

Databases are a ‘full body workout’ for Linux according to Josh Berkus. The CEO of PostgreSQL Experts had a session and a BOF at Linuxcon. The goals of these session was to make Linux developers aware of some of the special problems for databases and to get some hints of what database developers can do to better exploit Linux. Linux is the overwhelming OS choice for both the multi-process databases (PostgreSQL and Oracle) and the …